Structure of a Superhydrophilic Surface: Wet Chemically Prepared Rutile-TiO2(110)(1 × 1).

Surface X-ray diffraction has been employed to quantitatively determine the geometric structure of an X-ray-induced superhydrophilic rutile-TiO2(110)(1 × 1) surface. A scatterer, assumed to be oxygen, is found at a distance of 1.90 ± 0.02 Å above the five-fold-coordinated surface Ti atom, indicating surface hydroxylation. Two more oxygen atoms, situated further from the substrate, are also included to achieve the optimal agreement between experimental and simulated diffraction data. It is concluded that these latter scatterers are from water molecules, surface-localized through hydrogen bonding. Comparing this interfacial structure with previous studies suggests that the superhydophilicity of titania is most likely to be a result of the depletion of surface carbon contamination coupled to extensive surface hydroxylation.

Geometry of α-Cr2O3(0001) as a Function of H2O Partial Pressure.

Surface X-ray diffraction has been employed to elucidate the surface structure of α-Cr2O3(0001) as a function of water partial pressure at room temperature. In ultra high vacuum, following exposure to ∼2000 Langmuir of H2O, the surface is found to be terminated by a partially occupied double layer of chromium atoms. No evidence of adsorbed OH/H2O is found, which is likely due to either adsorption at minority sites, or X-ray induced desorption. At a water partial pressure of ∼30 mbar, a single OH/H2O species is found to be bound atop each surface Cr atom. This adsorption geometry does not agree with that predicted by ab initio calculations, which may be a result of some differences between the experimental conditions and those modeled.

Ecology of Increasing Diseases: Population Growth and Environmental Degradation.

The World Health Organization (WHO) and other organizations report that the prevalence of human diseases during the past decade is rapidly increasing. Population growth and the pollution of water, air, and soil are contributing to the increasing number of human diseases worldwide. Currently an estimated 40% of world deaths are due to environmental degradation. The ecology of increasing diseases has complex factors of environmental degradation, population growth, and the current malnutrition of about 3.7 billion people in the world.

Studies on the role of routes of allergen exposure in high IgE-producing beagle dogs sensitized to house dust mites.

The current study aimed to investigate the role played by oral, epicutaneous, and inhalation routes of exposure to house dust mites (HDM). The colony of high IgE-producing beagle dogs has been shown to develop pruritic dermatitis compatible with atopic dermatitis following environmental exposure (EE) to HDM. In crossover experiments, the response to EE was compared to two modified challenges, oral exposure (OE) and snood and muzzle exposure (SME). For OE, HDM were fed daily for 3 days. For SME, ingestion of allergen was prevented but there was inhalation and epicutaneous exposure to all body regions except to one ear. In all experiments, dogs were challenged for three consecutive days, and evaluated before, 6 h after exposure and daily thereafter, for 5 days. After a wash-out period, groups were crossed-over so that each dog was randomly challenged to all three protocols. Clinical scores were analysed using least squares analysis of variance. All dogs developed pruritic dermatitis regardless of the protocol. With OE, lesions developed in the same body regions as with EE although scores were lower. This difference became more evident after the first 3 days when OE scores decreased and EE scores continued to increase. The scores of covered and uncovered ears did not differ with SME. Scores for the remainder of the body were significantly lower than for EE. The development of lesions on covered ears supports the importance of inhalation or a systemic reaction to epicutaneous exposure in other areas. It is concluded that all routes are important and have additive effects, that route of exposure does not determine the distribution of lesions and that continuous epicutaneous exposure probably plays the most important role.

Investigation on the clinical efficacy and safety of 0.1% tacrolimus ointment (Protopic) in canine atopic dermatitis: a randomized, double-blinded, placebo-controlled, cross-over study.

Topical tacrolimus is successfully used in people with atopic dermatitis. Preliminary studies in dogs with atopic dermatitis using tacrolimus in a compounded lotion formulation indicated that tacrolimus significantly decreased erythema and pruritus according to investigator, but no significant improvement was reported by the dog owners. The objectives of this study were to evaluate the clinical efficacy and safety of the commercially available 0.1% tacrolimus ointment (Protopic) in dogs with atopic dermatitis. The study was designed as a double-blinded, placebo-controlled, cross-over study. Selected dogs were allocated to either tacrolimus or placebo for 4 weeks. After 4 weeks there was a wash-out period of 2 weeks and treatments were switched. Twelve dogs completed the study. Clinical signs were scored. Blood samples were collected for complete blood count, chemistry panels and tacrolimus levels at week 0 and 4 of each treatment. Tacrolimus ointment significantly decreased severity of symptoms for both owners and investigators at the end of the trial. When the same dogs received the placebo, there were no differences between week 0 and week 4 scores. Dogs with localized disease responded better than dogs with generalized disease. Tacrolimus was detected in the blood of animals receiving the active ingredient. Levels were below the level of toxicity and no adverse effects were reported in any of the dogs. No changes in complete blood count and chemistry parameters were detected between groups or within groups. In conclusion, tacrolimus appears to be a safe alternative treatment in dogs with atopic dermatitis, especially in those with localized disease.

Investigation on the effects of topical therapy with 0.1% tacrolimus ointment (Protopic) on intradermal skin test reactivity in atopic dogs.

Tacrolimus ointment (TAC) is an effective treatment for atopic dermatitis in humans and dogs. The purposes of the present study were to evaluate the effect of 4 weeks of TAC on intradermal skin testing (IST), and in case of suppression, to investigate if reactivity returned to baseline by 2 or 4 weeks post treatment. Intradermal skin test was performed using saline, histamine, lipopolysaccharide (LPS, 0.4 mg mL(-1)), house dust (25 PNU mL(-1)) and house dust mite (1 : 40 000 w/v) at weeks 0, 4, 6 and 8 on nine dogs enrolled in a blinded, crossover, clinical trial, using 0.1% TAC or placebo once daily for 4 weeks. Reactions were evaluated at 15 min, and at 4 and 6 h. Ointment was applied after the 15-min evaluation on weeks 0 and 4. Data were analysed using the statistical software SAS System for Windows. At week 4, TAC did not affect 15-min IST, but some reactions in the TAC group were suppressed at 6 h compared to baseline. In the TAC group, 4-h IST reactivity was reduced 2 weeks after discontinuation but returned to baseline by 4 weeks. In conclusion, TAC has no effect on immediate reactions but decreased some late-phase reactions. Therefore, no withdrawal is recommended to evaluate only immediate reactions, but a 4-week withdrawal may be necessary for evaluation of late-phase reactions.

Pilot study to assess the effects of early flea exposure on the development of flea hypersensitivity in cats.

This pilot study was to determine if early oral flea exposure reduces the incidence of flea allergy dermatitis (FAD) in cats. Eighteen kittens, assigned to three groups, received no flea exposure, oral flea exposure or flea infestation for 12 weeks. Then all the kittens were exposed continually to fleas for 31 weeks. Sensitization was monitored using intradermal testing (IDT), in vitro measurement of anti-flea saliva immunoglobulin E (IgE) and development of FAD. There was no statistically significant difference between groups in IDT reactions, in vitro data or clinical scores. The development of FAD was not associated with the presence of anti-flea saliva IgE. However, the development of a delayed reaction to flea bite was associated with symptoms after flea exposure. Although not statistically significant, the FAD scores in the oral group were lower than in the controls. Further studies are required to determine the role of oral flea exposure in the development of FAD in cats.

Double-blinded, placebo-controlled, cross-over pilot study on the efficacy of zileuton for canine atopic dermatitis.

Nine dogs meeting the diagnostic criteria for canine atopic dermatitis were enrolled in a double-blind, placebo-controlled, cross-over clinical trial. In this pilot study, zileuton (a 5-lipoxygenase inhibitor) given orally at 2 mg kg(-1) three times daily for 4 weeks significantly decreased erythema in dogs with atopic dermatitis but had no effect on pruritus. Zileuton was well tolerated and no adverse clinical signs were noted. However, one dog developed mild alanine aminotransaminase elevation, which resolved within 1 week of discontinuation of therapy. Monitoring of alanine aminotransaminase may be necessary in dogs receiving zileuton. Further studies with larger number of dogs are needed to evaluate the efficacy of zileuton as treatment for canine atopic dermatitis.

Intradermal skin test reactivity to histamine and substance P is blunted in dogs with atopic dermatitis.

Skin reactivity to intradermal injections (0.1, 0.5 and 1 nM) of substance P (SP) was evaluated in 20 clinically normal dogs and 20 dogs with atopic dermatitis (AD). Saline and histamine were used as negative and positive controls, respectively. Wheal diameters were measured. Reactions were evaluated for erythema and induration and a subjective score, on a scale from 0 to 4+, was given. Evaluations were performed at 3, 5, 10, 15 and 30 min after the injections. Wheal diameters for histamine and SP injections were significantly smaller in dogs with AD compared with clinically normal dogs. In both groups, reactions to the various concentrations of SP were not significantly different from each other and were always smaller than histamine reactions. Erythema was not seen with SP injections. In addition, subjective scores for SP injections were significantly lower in dogs with AD compared with controls. The results of this study are similar to those reported in human medicine, where a role for SP in AD is proposed and desensitization of receptors to both SP and histamine is hypothesized. Further studies are needed to investigate the role of SP in the pathogenesis of canine AD.

Sulphido-leukotriene production from peripheral leukocytes and skin in clinically normal dogs and house dust mite positive atopic dogs.

Pathogenesis of canine atopy has not been completely elucidated. In humans, sulphido-leukotrienes (s-LT) play a role in atopy, and increased production of s-LT occurs in the skin and peripheral leukocytes after allergen challenge. The study population included 16 clinically normal and 13 atopic dogs. All atopic dogs had in common a positive reaction (4+) to the intradermal injection of house dust mite (allergen of reference). Blood samples and skin biopsies were collected. Sulphido-LT synthesis by peripheral leukocytes after stimulation was measured, and no statistically significant difference was found between clinically normal and atopic dogs. Sulphido-LT concentrations in skin samples from stimulated and unstimulated sites were measured, and no statistically significant difference was detected between clinically normal and atopic dogs or between lesional and nonlesional skin within the atopic group. Clinical signs of atopic dogs were graded by owners and no correlation was found between their severity and cutaneous concentrations of s-LT. In this study there was no increase in s-LT synthesis in atopic dogs.

Pharmacokinetics of pentoxifylline in dogs after oral and intravenous administration.

OBJECTIVE: To evaluate the pharmacokinetics of pentoxifylline (PTX) and its 5-hydroxyhexyl-metabolite, metabolite 1 (M1), in dogs after IV administration of a single dose and oral administration of multiple doses. ANIMALS: 7 sexually intact, female, mixed-breed dogs. PROCEDURE: A crossover study design was used so that each of the dogs received all treatments in random order. A drug-free period of 5 days was allowed between treatments. Treatments included IV administration of a single dose of PTX (15 mg/kg of body weight), oral administration of PTX with food at a dosage of 15 mg/kg (q 8 h) for 5 days, and oral administration of PTX without food at a dosage of 15 mg/kg (q 8 h) for 5 days. Blood samples were taken at 0.25, 0.5, 1, 1.5, 2, 2.5, and 3 hours after the first and last dose of PTX was administered PO, and at 5, 10, 20, 40, 80, and 160 minutes after PTX was administered IV. RESULTS: PTX was rapidly absorbed and eliminated after oral administration. Mean bioavailability after oral administration ranged from 15 to 32% among treatment groups and was not affected by the presence of food. Higher plasma PTX concentrations and apparent bioavailability were observed after oral administration of the first dose, compared with the last dose during the 5-day treatment regimens. CONCLUSIONS AND CLINICAL RELEVANCE: In dogs, oral administration of 15 mg of PTX/kg results in plasma concentrations similar to those produced by therapeutic doses in humans, and a three-times-a-day dosing regimen is the most appropriate.

A Scoring Index for Clinical Signs of Flea Allergy Dermatitis in the cat.

This article describes the development, application, and validation of a scoring index for assessment of clinical signs in cats with flea allergy dermatitis (FAD). The Scoring Index for Clinical Signs of FAD was based on the evaluation and scoring of five signs over five anatomic areas, which is similar to the psoriasis area and severity index (PASI), a commonly used scoring method in human dermatology. The Scoring Index for Clinical Signs of FAD was used by different veterinarians to assess several groups of flea allergic research cats with varying signs of FAD. Analysis of the data shows a significant correlation and repeatability between investigators, making this a very useful scoring index.

Double-blind, placebo-controlled study to evaluate two miconazole conditioners for the treatment of Malassezia dermatitis in dogs.

Eighteen dogs with Malassezia dermatitis participated in a clinical trial to evaluate the efficacy of miconazole conditioners. Dogs were randomly assigned to receive vehicle only, miconazole 1%, or miconazole 2% conditioner. Conditioners were used three times weekly for 2 weeks and then twice weekly for 2 weeks. Investigators evaluated erythema, pruritus, and yeast counts weekly. Owners scored pruritus daily. Yeast number decreased in all treatment groups. Yeast number in the vehicle group was higher than in both the miconazole treatment groups but was not different between the two miconazole groups. Clinical scores decreased but no difference was detected among groups.

Comparison of anesthetic and cardiorespiratory effects of diazepam-butorphanol-ketamine, acepromazine-butorphanol-ketamine, and xylazine-butorphanol-ketamine in ferrets.

Ten ferrets were used in a crossover study to determine the sedative effects of intramuscularly administered diazepam (3 mg/kg body weight)-butorphanol (0.2 mg/kg body weight)-ketamine (15 mg/kg body weight); acepromazine (0.1 mg/kg body weight)-butorphanol (0.2 mg/kg body weight)-ketamine (15 mg/kg body weight); and xylazine (2 mg/kg body weight)-butorphanol (0.2 mg/kg body weight)-ketamine (15 mg/kg body weight). All of the ferrets became laterally recumbent following the administration of each drug combination. The xylazine-butorphanol-ketamine combination induced significantly longer (p less than 0.05) durations of tail-clamp analgesia (mean+/-standard deviation [SD], 81.0+/-19.1 min versus 20.5+/-25.4 min and 30.0+/-26.9 min), dorsal recumbency (mean+/-SD, 94.6+/-13.6 min versus 75. 6+/-34.7 min and 55.2+24.8 min), and muscle relaxation suitable for endotracheal intubation (mean+/-SD, 67.1+/-23.0 min versus 7.0+/-22.1 min and 9.5+/-15.4 min) than the diazepam-butorphanol-ketamine and acepromazine-butorphanol-ketamine combinations, respectively. The recovery time from dorsal recumbency to standing was not significantly different among the three treatment groups. The heart rate was significantly lower in the xylazine-butorphanol-ketamine group; however, systolic blood pressure was not significantly different among the treatment groups. Ventilatory function was more depressed in the diazepam-butorphanol-ketamine and xylazine-butorphanol-ketamine groups than in the acepromazine-butorphanol-ketamine group. A period (approximately 45 minutes) of hypoxia was observed in the xylazine-butorphanol-ketamine-treated ferret. Of the three combinations evaluated in ferrets, xylazine-butorphanol-ketamine was concluded to be the most effective anesthetic combination. However, hypoxemia and ventricular arrhythmias were observed in the xylazine-butorphanol-ketamine-treated ferrets, so the effectiveness of the xylazine-butorphanol-ketamine combination should be weighed against its cardiorespiratory side effects.

Effects of a microdose of medetomidine on diazepam-ketamine induced anesthesia in dogs.

OBJECTIVE: To evaluate cardiorespiratory and anesthetic effects of a microdose of medetomidine hydrochloride on diazepam-ketamine (DK) hydrochloride induced anesthesia in dogs. DESIGN: Randomized crossover study. ANIMALS: 6 two-year-old healthy female dogs. PROCEDURE: A study was designed to compare quality of anesthetic induction, recovery, analgesia, muscle relaxation, duration of immobilization, and ease of endotracheal intubation between diazepam-ketamine-medetomidine (DKM) and diazepam-ketamine induced anesthesia in 6 dogs. Diazepam (0.25 mg/kg [0.114 mg/lb] of body weight, i.v.) and ketamine (5 mg/kg [2.27 mg/lb], i.v.) with or without a microdose of medetomidine (5 micrograms/kg, i.v.) were administered to dogs. A baseline ECG was obtained, and baseline measurements of arterial blood gas tensions, arterial pressures, heart and respiratory rates, and minute volume were taken before drug administration. All measurements were repeated again 5, 10, 20, and 30 minutes after drug administration. Endotracheal intubation was attempted 1 minute after drug administration and then again 5, 10, 20, and 30 minutes after drug administration. Analgesia was evaluated by tail clamp and needle prick testing. RESULTS: Medetomidine improved quality of anesthetic induction, ease of endotracheal intubation, and extended duration of analgesia and lateral recumbency in anesthetized dogs. The addition of medetomidine to DK increased blood pressure and decreased heart and respiratory rates and minute volume. Hypoxemia was observed in 1 dog after DKM induced anesthesia. CLINICAL IMPLICATIONS: Administration of a microdose of medetomidine provides a useful adjunct to DK induced anesthesia in dogs. Oxygen insufflation is recommended for a minimum of the first 5 minutes of DKM induced anesthesia.

Evaluation of sedative and cardiorespiratory effects of diazepam-butorphanol, acepromazine-butorphanol, and xylazine-butorphanol in ferrets.

Ten ferrets were used in a crossover study to determine the sedative effects of intramuscularly (IM) administered diazepam (3 mg/kg body weight)-butorphanol (0.2 mg/kg body weight), acepromazine (0.1 mg/kg body weight)-butorphanol (0.2 mg/kg body weight), or xylazine (2.0 mg/kg body weight)-butorphanol (0.2 mg/kg body weight). All ferrets became laterally recumbent following the administration of each drug combination. The xylazine-butorphanol combination caused a significantly longer (p less than 0.05) duration of analgesia than the diazepam-butorphanol and acepromazine-butorphanol combinations. None of the ferrets could be intubated with any of the drug combinations. The time from induction to recovery was significantly shorter in the acepromazine-butorphanol-treated ferrets. A significantly lower heart rate was observed in the xylazine-butorphanol-treated ferrets; however, an acceptable systolic blood pressure was maintained. Ventilatory function was more depressed in the diazepam-butorphanol- and xylazine-butorphanol-treated ferrets than in the acepromazine-butorphanol-treated ferrets. Xylazine-butorphanol was found to be the best combination for use in ferrets.

Comparison of sedative and cardiorespiratory effects of diazepam, acepromazine, and xylazine in ferrets.

The sedative and cardiorespiratory effects of an intramuscular injection of diazepam (3 mg/kg body weight), acepromazine (0.1 mg/kg body weight), or xylazine (2 mg/kg body weight) in ferrets (n = 10, crossover design) was evaluated. Time from injection to assuming lateral recumbency was not significantly different between the three drugs. Duration of recumbency expressed as mean+/-standard deviation was significantly longer with xylazine (68.3+/-20.8 min) than with diazepam (43.2+/-8.2 min) or acepromazine (49.8+/-11.2 min). Sedation was graded to be the best in the xylazine-treated ferrets and worst in the diazepam-treated ferrets. Analgesia was judged only to be present following xylazine injection. Systolic blood pressure, oxyhemoglobin saturation, and end-expired carbon dioxide (CO2) were similar with all three drugs. It was concluded that, at the doses administered, xylazine provided better chemical restraint in the healthy ferret than either acepromazine or diazepam.

Comparison of anesthetic and cardiorespiratory effects of tiletamine-zolazepam-xylazine and tiletamine-zolazepam-xylazine-butorphanol in ferrets.

Nine ferrests were used in a crossover study to determine the anesthetic effects of intramuscular (i.m.) administration of a low dose of tiletamine-zolazepam (1.5 mg/kg body weight)-xylazine (1.5 mg/kg body weight); a high dose of tiletamine-zolazepam (3 mg/kg body weight)-xylazine (3 mg/kg body weight); and tiletamine-zolazepam (1.5 mg/kg body weight)-xylazine (1.5 mg/kg body weight)-butorphanol (0.2 mg/kg body weight). All ferrets became laterally recumbent within two minutes following the administration of each drug combination. The tiletamine-zolazepam-xylazine-butorphanol combination induced significantly longer (p less than 0.05) durations of tail clamp analgesia (mean +/- standard deviation [SD], 90.0 +/- 17.1 min versus 17.8 +/- 15.8 min and 41.9 +/- 26.3 min) and endotracheal intubation (mean +/- SD, 84.8 +/- 21.7 min versus 5.2 +/- 10.3 min and 26.3 +/- 29.8 min) than the low-dose tiletamine-zolazepam-xylazine and high-dose tiletamine-zolazepam-xylazine combinations, respectively. Heart rates and the times from dorsal recumbency to standing were not significantly different among the three treatment groups. However, systolic blood pressure was significantly lower in the tiletamine-zolazepam-xylazine-butorphanol group. Ventilatory function was more depressed in the tiletamine-zolazepam-xylazine-butorphanol group than in the low-dose tiletamine-zolazepam-xylazine and high-dose tiletamine-zolazepam-xylazine groups. A short period of hypoxia was observed in the tiletamine-zolazepam-xylazine-butorphanol-treated ferrets. Tiletamine-zolazepam-xylazine-butorphanol was found to be the best of the three combinations evaluated in these ferrets. The addition of butorphanol to the low-dose tiletamine-zolazepam-xylazine combination greatly enhanced the duration of analgesia, endotracheal intubation, and dorsal recumbency. However, since hypoxemia occurred during the tiletamine-zolazepam-xylazine-butorphanol anesthesia, oxygen (O2) insufflation is recommended. Doubling the dose of the low-dose tiletamine-zolazepam-xylazine increased the duration of analgesia and endotracheal intubation without prolonging the recovery when compared to the low-dose tiletamine-zolazepam-xylazine group.

An ultrahigh-vacuum chamber for surface X-ray diffraction.

An ultrahigh-vacuum environmental chamber for surface X-ray diffraction on Station 9.4 at the Synchrotron Radiation Source, Daresbury Laboratory, is described. Film growth can be monitored by simultaneously recording the Auger signal and the X-ray intensity at a particular point in reciprocal space. Such in situ measurements are essential for understanding the dynamic processes that occur during adsorption. An example is given in which the specularly reflected X-ray signal is correlated with Auger plots, during growth of Tl on Cu(001). In addition, the diffractometer and chamber combination allow large reconstructions to be investigated as shown by the in-plane structural analysis of the c(4x4) InSb surface. A study of the layer structure of Cr on Ag(001), in which an extended out-of-plane detector assembly was used, is also presented.